Enhanced valley polarization in WSe2/YIG heterostructures via interfacial magnetic exchange effect

Simultaneously Enhanced Emission and Valley Polarization of Dark Excitons of Monolayer WSe2 Using the Dual Effect of Strain and Magnetic Proximity

“…Figure summarizes the calculated valley polarization of excitons at positions A, B, and C, where valley polarization (P) is usually defined as P = false( I σ + σ + − I σ + σ − false) / false( I σ + σ + + I σ + σ − false) . The valley polarizations of bright exciton X 0 and bright trion X T at a temperature of 93 K without the magnetic proximity interactions are approximately 19% and 1.3%, respectively (point C), which are consistent with previous experiments . Note that the valley polarizations of the bright exciton X 0 is around 12.4% for the same monolayer WSe 2 on SiO 2 substrate (Figure S3).…”

“…The valley polarizations of bright exciton X 0 and bright trion X T at a temperature of 93 K without the magnetic proximity interactions are approximately 19% and 1.3%, respectively (point C), which are consistent with previous experiments. 36 Note that the valley polarizations of the bright exciton X 0 is around 12.4% for the same monolayer WSe 2 on SiO 2 substrate (Figure S3). Under the influence of magnetic proximity (point A), the valley polarizations of the bright exciton X 0 and bright trion X T increase to 23.4% and 19.8%, respectively.…”

“…Recent advances have demonstrated that site-controlled quantum emission from specific excitons, particularly enhanced emission from dark excitons, can be achieved using templates with prepatterned nanostructures . Furthermore, the valley polarization of bright excitons can be influenced by an yttrium iron garnet (YIG) substrate through the magnetic proximity effect. − Therefore, it is appealing to pose the following questions: Is it possible to simultaneously attain robust emission and elevated valley polarization of dark excitons using a prepatterned nanostructured YIG template? In other words, can we achieve robust emission and enhanced valley polarization of dark excitons through the combined influences of strain and magnetic proximity?…”

Controllable dual-polarization valley physics in the strain-engineered 2D monolayer of VC2N4

“…3,4 The advancements in valleytronics have primarily focused on the utilization of time-reversal-connected valleys, where valley polarization is dynamically or statically induced through external methods. 5–13 For example, it is well known that strain, 14,15 magnetic proximity effect, 16–19 and optical pumping 20,21 can be used to tune the energies of valleys. However, these methods suffer from various problems, such as a short lifetime of carriers, impurity scattering, and low efficiency.…”

Enhancement and modulation of valley polarization in Janus CrSSe with internal and external electric fields

“…In recent years, several methods for generating valley polarization have been proposed, including optical pumping, 29–31 breaking the crystal symmetry, 32 applied magnetic fields, 33,34 magnetic atom doping, 35,36 and the magnetic proximity effect. 10,11,13,37–43 Among them, the magnetic proximity effect is a particularly effective and accessible method for introducing large valley polarization in valley-polarized materials. For instance, the magnetic proximity effect of ferromagnetic substrates, such as Fe 3 GeTe 2 , 11 MnPS 3 , 10 yttrium iron garnet, 43 ScI 2 , 42 CoO, and MnO, 44,45 induces large valley polarization.…”